package org.codeart.juc.collection;

import java.util.concurrent.ConcurrentHashMap;

public class ConcurrentHashMapDemo {

    public static void main(String[] args) {
        ConcurrentHashMap<String, Integer> map = new ConcurrentHashMap<>();
        Integer r1 = map.put("a", 1);
        System.out.println(r1);

        Integer r2 = map.put("b", 2);
        System.out.println(r2);

        Integer r3 = map.put("c", 3);
        System.out.println(r3);
    }

}
